Toepler pumps



2 Sheets-Sheet 1 M. HANIN E A TOEPLER PUMPS Sept. 1, 1959 Filed May 14, 1956 //vVE/vmes JACQUES V054 7ZL 59 WW M Sept. 1, 1959 M. HANlN L 2,9

TOEPLER PUMPS Filed May 14, 1956 2 Sheets-Sheet 2 W e/Woes United States Patent TOEPLER PUMPS Mireille Hanin and Jacques Voeltzel, Paris, France, as-

signors to Institut de Recherches de la Siderurgie, St. Germain en Laye, France, a French professional institution Application May 14, 1956, Serial No. 584,855 Claims priority, application France February 3, 1956 Claims. (Cl. 230-83) It is known that the Toepler pump is a device intended to draw off, from a container, by fractions, certain amounts of gas so as to transfer them to another container, for example a graduated test-tube, for measuring purposes.

The conventionally known Toepler pump is operated by means of a two-way-cock which connects the device alternately to a vacuum and to a source of compressed or non-compressed air, in order that the mercury, which plays the part of a pump piston, may alternately receive displacements in both directions. It will be seen that the operation of such a device demands continual supervision since the operator has to act at near intervals to operate the two-Way cock.

Attempts have been made to render the operation of the Toepler pump automatic in several ways. Some devices ensure solely the automatic upward movement of the mercury; others control the movement of the mercury in both directions, by electromagnetic and/ or electronic means. These devices have not given satisfaction, however, their construction either being too complicated to enable the gases to be transferred for the purpose of collecting them, or the limiting vacuum obtained being too low, or else the mercury being delivered violently into the compression chamber, thus entailing grave risk of breakage of the latter.

The main object of the invention is to provide an automatic Toepler pump which obviates these drawbacks by means of an assembly of electric, electromagnetic and pneumatic means such as to permit a controlled upward and downward movement of the mercury, by the progressive admission of the pressure of the compressed air to the flask, that is to say the lower chamber, and by the controlled evacuation of the air by the vacuum, for the purpose of rapidly obtaining the limit pressure of the said Toepler pump.

Another object of the invention is to provide an automatic Toepler pump which comprises regulating and safety devices actuated by electromagnetic means and controlled by electric contacts operated by the mercury.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawing forming a part of this application and in which like numerals are employed to designate like parts throughout the same:

Figure 1 shows the assembly of an automatic Toepler pump device according to the invention; and

Figure 2 is a diagram of an exemplified remote control and safety device used in the said assembly.

According to Figure 1, the automatic Toepler pump illustrated comprises a flask 1 in to which the vacuum or compressed air is admitted by a two-way cock 2. To said flask is fitted a tank, that is to say a compression chamber 3, by means of a conical ground joint 4. The chamber 3 is connected on the one hand to a mercury valve, for example an automatic valve 5, which is in turn connected to a chamber 6 in which is disposed the gas to be drawn oif and, on the other hand, by means of a 1 2,902,208 7 Patented Sept. 1, 1959 capillary tube 7, of a total length close to barometric height, to a test-tube or bell 8 held in a mercury tank 9. The mercury valve illustrated in the drawing is a valve of the kind described in our co-pending patent application Ser. No. 573,437 of the 23rd of March, 1956.

Said tank 9 communicates at the bottom with another mercury tank 10 into which dip two electric contacts 11 and 12 terminating at predetermined and adjustable heights above the level of the mercury.

The two-way cock 2 causes the flask 1 to communicate on the one hand with the atmosphere at 13 and on the other hand, by means of a tube 14, either with the vacuum at 15 or with the tank 16 in communication with the compressed air at 17. Two cocks 18 and 19 control the admission of this compressed air into the tank 16 and into the tube 14. Furthermore, the tank 16 is in communication with an escape tube 20.

The fluid and vacuum controls are effected by means of the following device. A first electromagnetic valve 21, of known type, enables vacuum to be established and air to be readmitted alternately in the flask 1. Said valve is controlled by means of a cut-out box, or make-and break, for remote control 22, of known type, currently used in industry, by means of two relays 23 and 24 connected respectively to electric contacts, preferably of tungsten, 11 and 12. A second electromagnetic valve 25,1ikewise of known type, controls the escape tube 20. This valve is controlled by a relay 26 connected to a contact 27 placed in the upper part of the compression chamber 3. In the event of the mercury reaching a contact 28 disposed at a certain level, in consequence of accidental non-working of the valve 5, an electromagnetic relay 29 of known type and currently used in industry, disposed in the remote control box 22 supply, causes the make-andbreak to break. Finally, a general switch 30 disposed in front of the remote control and safety devices can break all the current of the installation. In the example in question, the switch 30 breaks a two-phase three-wire volt supply between phase and neutral, as shown in Figure 2.

The operation is as follows: when the vacuum is made on the Toepler pump, the level of the mercury in the tank 9 is at a distance 71 from the opening of the relieving capillary tube While the top of the said capillary tube is at a height close to the barometric height above the same level. It is necessary to provide a distance h sufiicient to make up for the variations in atmospheric pressure. If a re-admission of air is made under sufficient pressure in the flask 1, the mercury rises in the chamber 3. The automatic valve 5 closes the communication with the space to be drained off and the gas is delivered into the bell or test tube 8 of the tank 9 through the medium of the capillary tube 7. The mercury rises rapidly in the tanks 9 and 10 of small section. When the mercury reaches a certain height in the tank, the compressed air is shut ofi by the electromagnetic valve 21 and the chamber 1 again put under vacuum, the mercury redescends in the flask 1 and the barometric height is re-established after siphoning of the mercury at 9 and 10, while the automatic valve 5 is released. Pressure equilibrium is re-established between the chamber to be drained ofl and the chamber 3 and the operations can recommence.

The aforesaid operations are controlled by the electromagnetic relays under the action of the contacts 11, 12 described above, which in turn operate when they are touched by the mercury during the movements of the latter.

7 When the general switch 30 is open, there is no voltage over the whole of the installation and in particular over the electromagnetic valves 21 and 25. The flask 1 is under vacuum and there is pressure equilibrium between the container 6 to be drained OE and the chamber 3,

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the compressed air admitted by the cook 18 into the tank 16 playing the part of pressure flywheel escapes by the escape 20; the contacts 11 and 12 are open, consequently the relays 23 and 24 arenot energised. .The general switchfitlis Gllseththe relays Band 24 not being energised, i .e., their utilisation eirciiit being closed, thevalve 2 1 is undercurrent and permits the admission 'of compressed into the flask '1'. The air entering th latt ca s he'm c y to i s w in th h her 3; As .the' valve 25 is open when there is no voltage, it allows compressed air to escape through the tube '20 so that the pressure in the flywheel tank 16 tends towards atmospheric pressure.

The mercury reaching the contact 27, the relay 28 which is now under Voltage closes the circuit of the valve 25, so that all the pressure is admitted into the tank 1 6fland the flask 1.

i The mercury then rises more rapidly, closes the automatic valve 5 and escapes through the capillary tube 7, driving the gas into the hell or test tube 8 of the tank 9, in which the mercury rises.

' Until then the contacts 12 and 11 were open and the" circuits of utilisation of the relays 23 and 24 closed. The rising mercury begins by reaching the contact 11, thus resulting in the energising of the relay 23., then the contact 12, thus resulting in the energising of the relay 24-" T tWO r y bei n r s h rem t we 1 box 22'breaks and the valve 21, which is without current, restores the flask 1 to the action ofthe vacuum. The flask 1 being under the action of the vacuum, themercury passes'back from the tank 9 towards the chamber 3 and tends to re-establish the barometric height in the capillary tube 7. At that moment the contacts 12 andll become uncovered and the circuits of utilisation of the relays 24 and 25 close.' The "initial state is restored and the cycle recommences when the switch 30 is closed.

' The duration of the cycle depends on the difference in height between the contacts 11 and 12, and this difference in height is adjusted to correspond with the time required to restore equilibrium of pressure between the chamber 3 and the tank 6 to be drained off.

In one applied example which has been constructed, a minute and a half is suflicient to obtain pres'sure'equilibr'ium between the chamber 3 and the tank 6. The volume of gas that was tobe collected was approximately 3 'cc. Under these conditions, ten cycles, i.e., fifteen minutes, enabled a limit pressure to be obtained of less than or equal to 5 X mm. of mercury.

The following safety device is controlled by the abovementioned contact 28 and a ground contact 31 disposed at the top and bottom ends of the automatic valve 5. The contacts 28 and 31 and the ground, serve as a mercury switch in the circuit of the coil of the relay 29 (Figure 2,). When the mercury reaches the contact 28, it closes the circuit of the coil of the relay 29, which attracts its armature, thus breaking the supply of the make-and-break, which breaks; the valve 21 no longer being supplied with current, the flask 1 is replaced under vacuum. The coil of the relay 29 is then directly fed by the mains through the armature of the relay and the switch 32 which is still closed. When the mercury redescends, the circuit comprising the contacts 28 and 31 is open, but the coil of the relay 29 fed by the other circuit holds the cut-out box 22 in the open position and the valve 21 remains in the position of vacuum. After proceeding to the restoration of order, the operator opens manually the switch 32, thus cutting the auxiliary feeding of the relay 29. The armature thereof is made free, the box 22 closes the main circuit and a new cycle of the mercury ascending and descending may be started again: In order that the safety device may work in case of need, it is necessary to close the switch 32,.manually. In fact, ifthe mercury reaches the level of contact 28, there has been an operating fault, that is to say 4 failure of the valve to shut off, owing to a cause which must be found; for example a temporary balancing fault of the valve. When the cause has been found, the opera tor remedies it.

It will be seen that the above safety device enables the same operations to be carried out as those of a manually operated Toepler pump, but in a more rapid manner. The presence of the operator is necessary only o" Sen: andlsto p' the device.

The. emb dimen s ibed he inabo n illustrated in the drawings is naturally given solely by way ofexample and it is obvious that it can be modified in any appropriate manner in respect of form, the arrangement, the nature and the assembly of its elements without thereby departing from the; scope of the subjoined claims.

What we claim is:

1. In an automatic Toepler pump having a mercury circuit formed by a flask containing mercury, a closed tank connected thereto, an open mercury tank, a capillary tube connecting said closed tank and mercury tank, and mercury to circulate in said flask and tanks forming said mercury circuit, the combination of a source of pressure, a source of vacuum, pipe connections between said sources and said flask,'electric contacts located in said mercury circuit to be touched by the variations of level of mercury, purely electromagnetic relays connected with said contacts, and electromagnetic valves the electric circuits of which are included in the circuits of said electromagnetic relays mounted in said pipe connections to connect said flask alternatively to said sources of pressure and vacuum for causing mercury to rise or descend progressively.

2. The combination of claim 1 comprising further an escape tube communicating with the atmosphere connected to the pipe connection between the source of pressure and the flask, an electromagnetic valve mounted in said escape tube to equalize the pressure of admission of compressed air to the mercury, a relay to control said electromagnetic valve, and an electric contact in the upper portion of said closed tank connected to said relay and adapted to be engaged by mercury in said closed tank. i

3. In an, automatic Toepler pump having a mercury circuit formed by a flask containing mercury, a closed tank connected thereto, an open mercury tank, a capillary tubeconnecting said closed tank and mercury tank, and mercury to circulate in said flask and tank forming said mercury circuit, the combination of a source of pressure,

a source of vacuum, pipe connections between said sources and said flask, an electromagnetic valve mounted in said pipe connections to open or close them, a double control cut-out electrically connected to said electromagnetic valve, two electromagnetic relays connected to said double control cut-out, and two electric contacts placed in said open mercury tank at different heights respectively connected to saidelectromagnetic relays.

4. The combination of claim 3, which comprises further an automatic valve inserted between said flask containing mercury and said closed tank, an electric contact at the top end of said automatic valve, a relay connected to. said contact and tosaid double control cut-out, where- .by said electromagnetic valve is excited to open or 'close the connections between the sources of pressure and vacuum and theflask containing mercury.

5. In an automatic Toepler pump having a mercury c rcuit o med y a-flas containi g mer ury. a lo tank connected thereto, an open mercury tank, a capillary tube connecting said closed tank and mercury tank, mercury to circulate in said and tank forming said mercury circuit, a source of compressed air, a source of vacuum, duct means between said sources and said flask, electromagnetic valve mounted in sa d duct means vto open or close them, a double control cut-out electrically connectedto said electromagneticvalve, two electromagnetic relays connected-to said double control cute are e s r s me??? r i S QP WW References Cited in the file of this patent UNITED STATES PATENTS Nicolaus July 2, 1889 Rockwood Feb. 24, 1942 Glover et al Jan. 22, 1952 Schover June 29, 1954 FOREIGN PATENTS Switzerland Aug. 2, 1937 

